Eight People, One Year: Labor, Waste, and Ventilation
Grant the space and the stores, and the hardest onboard problem is still people. Eight of them, several thousand animals, and roughly a year.
Feeding a Floating World: Food, Water, and the Rain
Fitting bodies aboard is the easy part. Feeding them for about a year is where the arithmetic starts to bite, and where the difference between an assumption and a described system matters most.